The RV curve of n-on-p planar samples of long-wave HgCdTe detector prepared by B implantation was analyzed,the dark current mechanism under different bias voltage was studied,and the electrical parameters and ideal factors of the detector were extracted. The results showed that the better performance could be achieved by suppressing the trap-assisted tunneling current and the generation recombination current. The fitting analysis of the RV curve of the HgCdTe detector shows that the RV fitting technique can be used to evaluate the device performance and process state and guide the process improvement as an effective analysis method.